Heavy target barrel

I have been told that some Enfields used for target shooting have "heavy" barrels, now not being familiar with this particular style of rifle, I'm going to ask what may seem to be some odd questions.
Does anyone have one of these "heavy" barrels, either on a rifle or not, and could they measure the barrel diameter at about the 24" mark?
Now I'm looking to buy one of these heavy barrels if one is for sale, but I would prefer a shot out one as I intend having it re-bored to a larger calibre and fit it to an LSA No.1 action that I have recently picked up.
I am trying to buy one in the States and have a cousin who lives there send it to be re-bored and then on to me.
As stupid as it sounds, it is still way cheaper this way than buying a new barrel here in Oz.....

Roger

Yuma I will dig out my H marked Lithgow barrel and measure for you .

years ago I was told you could mate a Browning MG barrel to an Enfield action. 

RichardSuhkoi wrote: years ago I was told you could mate a Browning MG barrel to an Enfield action.  These used to be available but are now rare so useless advice, sorry.  The 5 groove BREN bore from Long Branch was I think incorporated into all Long Branch barrels after maybe 1949? This sort of supports the MG barrel idea.  I think an Enfield with a big heavy barrel would also look good.

Thanks, every bit helps

Roger